docs: fix four verified broken links from #1786

[mohammedmessaoudene-cmd]

Proposed changes

This documentation-only change corrects four unambiguous broken links reported in #1786:

• replace the retired Hyperledger wiki Code of Conduct URL with the LF Decentralized Trust page
• use the current .html URLs for the Fabric chaincode lifecycle, Fabric connection profile, and Solidity installation pages

This intentionally addresses only these four verified links and does not claim to close every item in #1786.

Related to #1786.

Types of changes

• Documentation update

Validation

• all four replacement destinations returned HTTP 200 on 20 September 2026
• python -m mkdocs build completed successfully from doc-site/requirements.txt
• the emitted warnings concern other pre-existing links or configuration
• git diff --check passed

Checklist

• I have read the contributing guidelines.
• I have performed a self-review of the change.
• I have signed off on the commit under the DCO.
• The documentation build completes successfully.
• The change introduces no new warning attributable to these substitutions.

AI assistance was used to identify, test, and review these substitutions. I reviewed the diff and validation results before submission.

[EnriqueL8]

thanks @mohammedmessaoudene-cmd